There are, as I said, many similarities between Islam and Christianity, and many substantial differences. A book is very close to the heart of both religions for Islam that book is the Koran and for Christians the Bible, consisting of the Hebrew Scriptures and the New Testament.
The Bible, strictly speaking, is not a book it is a collection of books all of which Christians believe to be equally inspired, that is “God-breathed.” One part is not necessarily more inspired than the other. The Bible is filled with historical narrative. Many parts of it read like an adventure story.
The Koran is completely different. The Koran has practically no narrative at all. It is simply a collection of sayings, not the sayings of Muhammad but the sayings of Allah. It can be thought of as a non sequential conversation between Allah and Muhammad by means of the Angel Gabriel. It is not the speaking of any man nor the opinion of any man. It is Allah who is the speaker and as such, the book should not be interpreted, or in the view of some, even translated from the very poetic, complex and ancient Arabic in which Allah first spoke it. To change the book is to change the speaking of Allah, and as such is blasphemous.
Christians, on the other hand are always translating and amending the translation and reworking the text as better ancient scrolls are found. In Islam this sort of treatment for the Koran would be unthinkable. Muhammad never wrote anything. The same is true of Jesus. His followers would remember or write down the things that Allah had told Muhammad and these were collected by them after Muhammad’s death in 632.
They are not necessarily written down in the order in which they were spoken by Allah to Muhammad. This is important to remember. Much hinges on when apparently conflicting verses of the Koran were written. In addition to the Koran, there exist texts called the Hadiths, or acts and sayings of Muhammad that teach the Muslim way of life. They were set down about a century after the death of Muhammad, and there is dispute about which Hadiths are authentic. The Hadiths in no way are comparable to the Koran, but they support it. There are some words of Allah in the Hadiths which some Muslims hold on the level of the Koran, but in Islam the Koran stands alone. Muhammad was simply speaking for Allah. He put none of his own opinions in the text.
For instance the 4th chapter (surah), 34th verse of the Koran says:
“Men have authority over women because God has made the one superior to the other, and because they spend their wealth to maintain them. Good women are obedient. They guard their unseen parts because God has guarded them. As for those from whom you fear disobedience, admonish them and send them to beds apart and beat them. Then if they obey you, take no further action against them. Surely God is high, supreme.”
This is not Muhammad’s opinion. This is Allah’s opinion, if one may say it that way. It is the infallible and unchangeable speaking of Allah. It can not be interpreted, modernized or nuanced. It is the divine command. On the other hand, the precise nature of the veiling of women is not made clear in the Koran, though it is clear in the verse quoted that women should be veiled. The Hadiths indicate that Muhammad taught a woman should show only her face and hands. The authenticity of each Hadith is discussed and there is room for interpretation regarding the Hadiths, and thus the nature of the veiling of women. That is why you see so many forms of the hijab, or veiling.
There is another very interesting similarity between Christianity and Islam, the doctrine of abrogation or “naskh.” Surah 2:106 says, “None of Our revelations do We abrogate or cause to be forgotten, but We substitute something better or similar. Knowest thou not that Allah hath power over all things?” This means that nothing abrogates the Koran except the Koran. Naskh (abrogation) is a kind of gradual revelation.
Allah revealed his truth to Muhammad over the course of 20 years, gradually introducing Muhammad and his followers to more difficult and fuller truths. The problem with this is the dispute over the chronology of the verses. If one verse seems to contradict another, it is only an appearance because the later and fuller verse abrogates the earlier verse. The time at which a word was received by Muhammad is thus a matter of the greatest importance.
Which came first, Sura 8.12 which says, “Remember thy lord has inspired the angels with the message. Give firmness to the believers and instill terror into the hearts of the unbelievers. Smite them above their necks and smite the fingertips of them,” or “Let there be no compulsion in religion” Surah 2:256? It’s a rather important question. Surah 9:5 is called the “Verse of the Sword” and has caused no end of controversy. “When the sacred months are over slay the idolaters wherever you find them. Arrest them, besiege them, and lie in ambush everywhere for them. If they repent and take to prayer and render the alms levy, allow them to go their way. God is forgiving and merciful.”
Some Muslim modernists insist that verse applies only to the battle of Badr, but the history of Islam is in fact one of unremitting war. The general rule of thumb is that the earlier verses of the Koran revealed in Mecca are superseded by those revealed later at Medina. When the Muslims were still at Mecca they were too few in number to make war. When they were at Medina, they were better organized and stronger and thus Allah revealed his plan for the conquering armies of Islam and his goal of making the world subject to Sharia (Islamic Law) revealed in the Koran. The direction of abrogation is from word to sword, from critique to warfare.
Christianity too, has a kind of doctrine of abrogation, the New Testament abrogating the old. Jesus explain this in his teaching on divorce. Matthew 19:8 “Jesus replied, 'Moses permitted you to divorce your wives because your hearts were hard. But it was not this way from the beginning.'” What had been allowed in the covenant of Sinai was not to be allowed in the covenant of Calvary. The covenant of Calvary is meant to return Christians to the primeval innocence of the Garden of Eden.
Thus Christians don’t stone adulterers or sorcerers, though this is commanded in the Law of Moses. They don’t permit divorce and above all don’t permit any violence that is not clearly self defense. The Christian form of abrogation is a turning away from violence. Christianity too has its own verses of the sword. When Jesus was being arrested he refused to let his disciples defend him. “Put your sword back in its place,” Jesus said to (Peter) him, “for all who draw the sword will die by the sword.” And again: Matt 5:38,39 “You have heard that it was said, 'Eye for eye, and tooth for tooth. But I tell you, Do not resist an evil person. If someone strikes you on the right cheek, turn to him the other also.” This abrogates Deuteronomy 19:21, “Show no pity: life for life, eye for eye, tooth for tooth, hand for hand, foot for foot.” The Koran seems to side with Deuteronomy. (Surah42:42) “But there is no blame on those who defend themselves after they have been wronged.” This is amplified by Surah 2:193: “Persecution is worse than slaughter.” This is usually taken to mean that religious persecution is the greatest offense and the greatest grounds for violent action.
So we share the concepts of Sacred Scripture and the concept of abrogation, but in these ideas Islam and Christianity are as different from each other as can be. There is very clearly a sword at the heart of Islam while there is a cross at the heart of Christianity.